Simulate CPU load with Python

While testing out some home automation code on my Raspberry Pi I noticed it was pretty CPU intensive. Time to bump up the overclock to squeeze more performance out of the Broadcom Arm7 processor. I wanted to keep an eye on temps as well as stability under full load so I needed to simulate CPU usage.

This small Python script will do the job. It uses the multiprocessing library which you can read more about here.

#!/usr/bin/env python
"""
Produces load on all available CPU cores

Updated with suggestion to prevent Zombie processes
Linted for Python 3
Source: 
insaner @ https://danielflannery.ie/simulate-cpu-load-with-python/#comment-34130
"""
from multiprocessing import Pool
from multiprocessing import cpu_count

import signal

stop_loop = 0


def exit_chld(x, y):
    global stop_loop
    stop_loop = 1


def f(x):
    global stop_loop
    while not stop_loop:
        x*x


signal.signal(signal.SIGINT, exit_chld)

if __name__ == '__main__':
    processes = cpu_count()
    print('-' * 20)
    print('Running load on CPU(s)')
    print('Utilizing %d cores' % processes)
    print('-' * 20)
    pool = Pool(processes)
    pool.map(f, range(processes))

This will utilize each CPU core and produce ~100% load with the while loops calculation.

--------------------
Running load on CPU(s)
Utilizing 8 cores
--------------------